As use of vehicles is becoming more common, the volume of traffic is rapidly increasing. In proportion to this, the number of traffic accidents is also increasing. Furthermore, as a high-speed travel resulting from the improvement in performance of vehicles has become widespread, the number of large accidents causing large loss of life and property is also increasing.
Of vehicle accidents, a collision of a vehicle with road safety facilities is an accident in which only a single vehicle is involved. Inexperience, carelessness, or drowsiness is known as the primary reasons for single-vehicle accidents.
To prevent collision accidents with road facilities, various efforts including maintenance of road safety facilities, campaigns for increasing driving safety, etc. must be made. However, such efforts alone to prevent single vehicle accidents are not sufficient. Therefore, safety facilities for shock absorption have been installed at places where there are possibilities of single-vehicle accidents.
Guardrails and crash cushions installed ahead of the guardrails are representative examples of safety facilities for shock absorption. Guardrails function to absorb shocks mainly caused by side collisions. Crash cushions function to absorb shocks caused by frontal collisions. An example of such crash cushions was proposed in Korean Patent Registration No. 10-1267446 (May 31, 2013), entitled “CRASH CUSHION FOR ABSORBING SHOCK IN COLLISION OF VEHICLE WITH FRONT PART OF GUARDRAIL.”
Such a crash cushion must have the capability to absorb shock transmitted from a high-speed traveling vehicle and to minimize damage. Therefore, a structure that can effectively absorb shock is essentially required for the crash cushion.